Verb
(chiefly US, literally) To fire all of the cartridges in the magazine of an automatic or semi-automatic firearm.
(chiefly US, idiomatic, sports, by extension) To compete with great vigor, especially by making numerous scoring attempts.
(chiefly US, idiomatic, by extension) To speak vehemently, especially in an outraged, insulting, or threatening manner.
Source: en.wiktionary.org